Telephone-switchboard.



PATENTEDAUG. 29, 1905. J. L. WRIGHT.

TELEPHONE SWITGHBOARD.

APPLICATION FILED JULY 28, 1904.

2 SHEETS-SHEET 2.

alike: M1 4 JOSEPH L. WVRIGHT, OF CLEVELAND, OHIO.

TELEPHONE-SWITCHBOARD.

Specification of Letters Patent.

Patented Aug. 29, 1905.

Application filed July 28, 1904. Serial No, 218,509-

1 To a whom it may concern:

Be it known that I, J OSEPH L. WRIGHT, a citizen of the United States,residing at Cleveland, in the county of Ouyahoga and State of Ohio, haveinvented new and useful Improvements in Telephone-Switchboards, of whichthe following is a specification.

This invention relates to telephone-switchboards, and has for aparticular object the construction of a switchboard wherein the use ofconductors connecting the plugs is avoided, and is characterizedparticularly by a construction wherein the connections instead ofterminating in plugs and cords terminate in rows of connecting-stripsmade up in pairs. Jacks and'plugs of novel construction are used withthese strips. The jacks are sliding jacks, comprising two pieces ofspring-metal insulated from each other and having contact at each endwith the strips and the bus-bars on each side of the lines. These jacksare moved by plugs, which vary in length according to the number ofconnecting-lines and comprise pairs connected with a string to showwhich two parties are connected. The pairs of plugs move the slidingline-jacks, the first of the pairs to the first and secondconnecting-strips, the second to the third and fourth connecting-strips,and so on up to the last pair of plugs, which move the jack to the lastpair of connecting-strips. The plugs have heads on the inner end, whichcatch behind springs on the outer ends of the jacks to restore them tonormal position when the plugs are withdrawn.

The invention is illustrated in the accompanying drawings, whereinFigure 1 is a diagrammatic elevation of a fifty-line switchboard,showing one layer of the talking-circuit connecting-strips. Fig. 2 is ahorizontal sectional view showing the sliding jacks andtalking-circuits. Fig. 3 is an end view showing the connecting-strips.Fig. 4 is a diagram of the various talking, listening, and signalconnections, indicating the bus-bars B and the first two of theconnecting-strips G of two lines. Figs. 5 and 6 are plans of two of theplugs, the shortest and longest, respectively. Fig. 7 is a plan of apair of plugs attached together.

Referring specifically to the drawings, the sliding jacks are indicatedat J, the connecting-strips at O, and the plugs atP. The

lines end in strips L, and the bus-bars are connected to terminals S forconvenlence 1n wiring.

Each jack consists of two spring-metal pieces secured to and separatedby pieces of insulating material ,7". The spring-metal pieces 1' areflared at the ends, as at 1' to contact with the strips L and theconnectingstrips C. When in normal position, the jacks are in contactwith the first bus-bar strip B and the strips L, which are thusconnected with line-signal. The connecting-strips O are made up in pairsand rows and are separated by strips 0 of insulating material. Allstrips on each side are connected, as shown in Fig. 1, one side beingmarked Tip and the other side Sleeve on the drawings, and

these strips are then wired to the regular ringing and listening keys,as marked on the diagram Fig. t, by wires we 11/ .2 and w, y, and .2. Inother words, all the strips C in row No. 1 on the sleeve side areelectrically connected to each other, and all of the strips in said rowon the tip side are similarly connected to each other, (see Fig. 1,) andthe same is true with respect to the strips in every row. Two rows ofconnecting-strips are required for each key, one on each side, as willbe understood, the first row being wired to the calling part of firstregular key and the second to the answering part, and the third andfourth row being, respectively, wired to the calling and answering partsof the second regular key, and so on. This is necessary to preventcentral ringing in the ear of the calling party. There will therefore betwenty rows of connecting-strips, as shown in the drawings by thenumerals 1 to 20, to ten key-circuits. The insulating material 0 betweenthe connecting-strips preferably pIOJBClJS slightly to prevent thejack-contacts from touching the metal strips as it passes over them.

There is one pair of plugs to each ringing and listening key, and theyare conveniently placed before the operator in front of the face of thejack-plate A, which is provided with holes (0 equal to the number oflines. Each pair of plugs is connected by a string K to show which twoparties are connected. The plugs vary in length. The shortest is justlong enough to move the sliding jack to the first row (row 1) ofconnecting-strips O, and the longest will be long enough to move thejack to the last row, (row 20.) The shortest pair are placed oppositethe first key, and so on, the longest being opposite the last key. Eachplug has a shoulder 12 where it joints its handle H, and the shouldercontacts with the face-plate A when the plug is shoved in the hole, andthereby limits its movement. The difference in length between the twomembers of each pair of plugs is equal to the distance between themiddle lines of the connectingstrips. Consequently each plug moves thejack to a particular strip and its mate to the next strip and the pairconnect difierent strips from any other pair. Thus the plugs of thefirst or shortest pair move the jacks to the first and second rows,respectively, of connectingstrips, the second pair to the third andfourth rows, and so on. Each plug has a head D, adapted to catch over aspring cl, projecting from the front end of the jack, to pull the jackback to original position, after which the spring will yield to allowthe removal of the plug.

In operation supposing subscriber N0. 10 wishes to talk to No. 1. Heoperates his line signal through line connections L, jack J, bus-bars B,and connections S. The operator thus called may use any pair of plugsdesired or available, since each pair will connect any two lines, oneplug acting to connect one line to the calling part of the keycorresponding to the pair of plugs and the other plug acting to connectthe other line to the answering part of the key, so they are connectedto each other. Assuming the pair shown in Fig. 7 and assuming that thelines shown in Fig. t are lines 1 and 10, the right-hand plug is placedin No. 10 and is of proper length to move the jack to the second row ofconnecting-strips, as shown in Fig. 4:, which are wired to the operatorskey and enables the operator to throw her lever to listening positionand ask the number desired. On learning that N o. 1 is the party wanted,she places the other plug of the pair in No. 1, which moves the slidingjack to the first row of strips, and as these strips are wired to thecalling part of the first key movement of the lever to ringing positionrings up No. 1. The necessity for the two rows of connecting-stripsconnected to each key can now be seen, since if both plugs were the samelength and both lines connected to the same strip the operator wouldring in the ear of the calling party. Hence, as said before, one of thestrips is connected to the ringing part of the key and,

the other to the answering part. The lever is then thrown to normalposition, leaving No. 10 and No. 1 connected in the ordinary manner. Anysuitable known type of operators key may be used. Fig. 4 shows in diagram the connections produced in the instance just described. Referringtheretosay the line on the right is line10 and that on the left linelthe circuit may be traced from 10 to 1 as follows: in one of the stripsL, through one of the side pieces of the jack J, strip 0 wires 00 1 toand through the key, Wires 1/ a? to strip C, one side of jack J,linestrip L, other side of jack J, other strip 0, linez, to and throughthe key, line .2, to, finally,

strip O and line L of line 10. Although only two rows of strips C, rows1 and 2, are shown in Fig. 4, it is obvious that the same connectionswould be established with any pair of plugs, since the jacks wouldsimply be pushed in farther and instead of connecting rows 1 and 2 wouldconnect 3 and 4 or5 and 6, or otherwise, according to the pair of plugsused. To disconnect, the operator pulls out the plugs, which by means ofthe head and spring-catch described restore the jacks to originalposition in contact with signal bus-bars B. The line-signal beingconnected to the bus-bar B in front of the first row ofconnecting-strips will be disconnected at first movement inward ofsliding jack. This arrangement does away with the tinsel conductingcordsbetween plugs, which are continually wearing and cutting out.

The plugs can be made in one solid piece and arecheaper than the plugswith insulated parts. Only one weight will be needed to a pair of plugsinstead of two. i

The sliding jack can be made cheaper'than the ordinary spring-jack.There is no danger of the line-signal being left on during conversation,because the bus-bars B are disconnected as soon as the plugs are pushedin. The contacts are positive, all strips in each row ofconnecting-strips being joined by a solid piece of metal, and this inturn is connected direct to the ringing and listening key.

What I claim as new, and desire to secure by Letters Patent, is-

1. In a switchboard, the combination with a plurality ofconducting-strips arranged in pairs and insulated from each other, andlineterminals, of jacks having contact with the terminals and movableover the strips to connect desired pairs thereof.

2. In a switchboard, the combination with bus bars and operators devicesconnected thereto, line terminals, and a plurality of pairs ofconductingstrips,of jacks having contact with the terminals and normallywith the bus-bars, and movable over the strips to connect desired pairsthereof.

3. In a switchboard, the combination with a plurality of line-terminals,of aplurality of pairs of conducting-strips made up in rows, theopposite members of the various pairs being electrically connected, andjacks having connection with the terminals and movable over the stripsto connect the terminals with desired rows of pairs.

4. In a switchboard, the combination with a series of pairs ofconducting-strips, and lineterminals, of a jack havingconducting-pieces, insulated from each other, between the terminals andstrips, and movable to connect the terminals with any desired pairofstrips.

5. In a switchboard, the combination with line-terminals, and aplurality of pairs of conducting-strips, of jacks slidable along theterminals and over the several pairs of strips,

IIS

and plugs engageable with the jacks to move the same, the plugs being ofdifierentlengths.

6. In a switchboard, the combination with line-terminals, anda-plurality of pairs of conducting-strips, of jacks having contact withthe terminals and movable contact with the several pairs of strips, andplugs engageable with the jacks to move the same, the plugs beingarranged in pairs, each pair having a member of different length from amember of any other pair.

7 The combination with the line-terminals, and the insulatedconducting-strips arranged in a series opposite the same, of a jackslidable along the terminals and across the strips, said jack havingconducting-contacts between the terminals and any of the strips,respectively on opposite sides of the circuit.

8. The combination with the line-terminals and the insulatedconducting-strips arranged in a series opposite the same, of a jackslidable along the terminals and across the strips, said jack havingcond uoting-contacts between the terminals and strips, respectively onopposite sides of the circuit, and a plug having detachable engagementwith the jack, to move the same back and forth.

, 9. In a switchboard, in combination, a plurality of lines and theirterminals, a plurality connected with each other, a plurality of jackseach of which is electrically connected with the terminals of one of thelines and is movable over the pairs of conducting-strips to connect therespective members of any pair thereof with the terminals, and plugsarranged in pairs and engageable with the jacks to move the same, eachpair having members of different lengths.

10. In a switchboard, in combination, a plurality of lines, a pluralityof pairs of conductingstrips arranged in rows, the opposite members ofeach pair being electrically con nected with the similar members of theother pairs, a jack connected to each line, and movable across the rowsto connect the same with any pair of strips, an operators key theringing part of which is connected to one pair of strips and theanswering part of which is connected to another pair of strips, and apair of plugs corresponding to the key and engageable respectively withthe jacks to move the same to the pairs of strips so connected.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

JOSEPH L. WRIGHT.

Witnesses:

JOHN A. BOMMHARDT, LOTTIE N EWBURN.

